Special superplasticizer used for concrete with high and ultrahigh strength and preparation method thereof

Abstract

The invention discloses a special superplasticizer used for concrete with high and ultrahigh strength and a preparation method thereof. The preparation method for the superplasticizer provided by theinvention comprises the following steps: initiating a solvent, a polymerizable monomer A, a chain transfer agent B, a polymerizable monomer I and an initiator to polymerize so as to obtain an intermediate solution; then adding polyether C, amino acid D and micromolecular peptide E, and simultaneously adding an auxiliary reaction reagent F so as to obtain an intermediate mixed solution; and addingthe intermediate mixed solution into a mixed solution of water and a phosphoric acid composition G which is dissolved in a solvent so as to obtain a solution of the superplasticizer. Compared with a commercially-available ordinary superplasticizer, the superplasticizer provided by the invention has the following advantages: when the superplasticizer is applied to high-strength concrete with a strength grade of C50 or above, the usage amount of the superplasticizer can be significantly reduced to achieve a same fluidity; the workability is significantly improved under same fluidity conditions;the inverted slump cylinder emptying time is shortened; the viscosity is reduced; and when the superplasticizer is applied to ultrahigh-strength concrete with a strength grade of C100 or above, the advantages of the superplasticizer are more prominent, and the usage amount and viscosity of the superplasticizer can be significantly reduced.

Description

technical field [0001] The invention relates to the field of superplasticizers used in concrete, in particular to a special superplasticizer for high- and super-high-strength concrete and a preparation method thereof. Background technique [0002] The term "concrete" is used here generally indiscriminately to mean concrete such as concrete, mortar or grout, and this applies elsewhere in this document as well. [0003] Since the invention of high-performance water reducer (polycarboxylate water reducer), it has been widely used and developed greatly, and it has become an indispensable component in concrete. Generally, the polycarboxylate superplasticizer is a comb-shaped structure, which is generally prepared by free radical polymerization of vinyl monomers, and its main chain (generally -CH 2 -CH 2 - Structural or functional group substituted =CH-CH 2 - structure) is connected with charged functional groups (such as carboxyl, sulfonic acid groups, etc.), and the correspon...

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Problems solved by technology

Ordinary water reducers have weak adhesion on the surface of low / weak electric particles, and cannot effectively cover all powder particle surfaces

In medium and low-strength concrete, the volume fraction of solid particles is not high, and this effect is not obvious; but in high / ultra-high-strength concrete, the volume fraction of solid particles is high, and ordinary water reducing agents have limited weakening of the friction between particles, resulting in slurry High viscosity, difficult construction

[0006] However, the above-mentioned existing new technology (water reducer products) failed to solve the problem fundamentally. These water reducers have not been specially designed, and their adhesion to the surface of weakly charged or negatively charged particles is weak, and they cannot adhere to the surface of all particles. Effective coverage, so the concrete viscosity is still high, the effect is very limited, the water-binder ratio of the reported concrete is mostly between 0.2-0.35, which belongs to conventional high-strength concrete, and rarely involves ultra-high-strength concrete

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